#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

int main(int argc, char *argv[])
{
	struct tm tm;
	time_t t;

	putenv("TZ=America/Chicago");

	printf("Testing 1994-10-29 01:00:00 (DST)\n");

	memset(&t, 0, sizeof(t));
	tm.tm_year = 94; tm.tm_mon = 9; tm.tm_mday = 29; tm.tm_hour = 1; tm.tm_min = 0; tm.tm_sec = 0; 
	tm.tm_isdst = 0;
	t = mktime(&tm);
	printf("isdst=0  -> %d, isdst=%d\n", t, tm.tm_isdst);

	memset(&t, 0, sizeof(t));
	tm.tm_year = 94; tm.tm_mon = 9; tm.tm_mday = 29; tm.tm_hour = 1; tm.tm_min = 0; tm.tm_sec = 0; 
	tm.tm_isdst = -1;
	t = mktime(&tm);
	printf("isdst=-1 -> %d, isdst=%d\n", t, tm.tm_isdst);

	memset(&t, 0, sizeof(t));
	tm.tm_year = 94; tm.tm_mon = 9; tm.tm_mday = 29; tm.tm_hour = 1; tm.tm_min = 0; tm.tm_sec = 0; 
	tm.tm_isdst = 1;
	t = mktime(&tm);
	printf("isdst=1  -> %d, isdst=%d\n", t, tm.tm_isdst);

	printf("Testing 1994-10-30 01:00:00 (could be either)\n");

	memset(&t, 0, sizeof(t));
	tm.tm_year = 94; tm.tm_mon = 9; tm.tm_mday = 30; tm.tm_hour = 1; tm.tm_min = 0; tm.tm_sec = 0; 
	tm.tm_isdst = 0;
	t = mktime(&tm);
	printf("isdst=0  -> %d, isdst=%d\n", t, tm.tm_isdst);

	memset(&t, 0, sizeof(t));
	tm.tm_year = 94; tm.tm_mon = 9; tm.tm_mday = 30; tm.tm_hour = 1; tm.tm_min = 0; tm.tm_sec = 0; 
	tm.tm_isdst = -1;
	t = mktime(&tm);
	printf("isdst=-1 -> %d, isdst=%d\n", t, tm.tm_isdst);

	memset(&t, 0, sizeof(t));
	tm.tm_year = 94; tm.tm_mon = 9; tm.tm_mday = 30; tm.tm_hour = 1; tm.tm_min = 0; tm.tm_sec = 0; 
	tm.tm_isdst = 1;
	t = mktime(&tm);

	printf("isdst=1  -> %d, isdst=%d\n", t, tm.tm_isdst);

	printf("Testing 1994-11-01 01:00:00 (not DST)\n");

	memset(&t, 0, sizeof(t));
	tm.tm_year = 94; tm.tm_mon = 10; tm.tm_mday = 01; tm.tm_hour = 1; tm.tm_min = 0; tm.tm_sec = 0; 
	tm.tm_isdst = 0;
	t = mktime(&tm);
	printf("isdst=0  -> %d, isdst=%d\n", t, tm.tm_isdst);

	memset(&t, 0, sizeof(t));
	tm.tm_year = 94; tm.tm_mon = 10; tm.tm_mday = 01; tm.tm_hour = 1; tm.tm_min = 0; tm.tm_sec = 0; 
	tm.tm_isdst = -1;
	t = mktime(&tm);
	printf("isdst=-1 -> %d, isdst=%d\n", t, tm.tm_isdst);

	memset(&t, 0, sizeof(t));
	tm.tm_year = 94; tm.tm_mon = 10; tm.tm_mday = 01; tm.tm_hour = 1; tm.tm_min = 0; tm.tm_sec = 0; 
	tm.tm_isdst = 1;
	t = mktime(&tm);
	printf("isdst=1  -> %d, isdst=%d\n", t, tm.tm_isdst);

	return 0;
}